The present invention relates to certain novel aryloxyphenoxyalkanoates and alkenoates, and to the R-enantiomers thereof which are useful as herbicides. The present invention also relates to herbicidal compositions containing these novel compounds; to methods of using these compounds for the control of weeds in noncrop areas as well as in the presence of valuable crops; and to novel intermediates used to make these compounds.
Various aryloxyphenoxyalkanoates, including 4-(phenoxyphenoxy)propionic acids are known as herbicidal agents. U.S. Pat. No. 4,332,961 discloses .alpha.[4-(4-trifluoromethylphenoxy)phenoxy]alkane carboxylic acid and derivatives thereof wherein the "4-(trifluoromethyl)phenoxy group" may optionally contain a chloro substituent. U.S. Pat. No. 4,332,960 discloses .alpha.[4-(2'-hydrogen or halogen-4'-(trifluoromethyl)phenoxy)phenoxy]propionic acid and derivatives thereof wherein hydrogen is the preferred substituent at the 2' position. Both of these patents teach the compounds disclosed in them as possessing herbicidal activity.
U.S. Pat. No. 4,370,489 discloses .alpha.[4-(2'-chloro-4'-bromophenoxy)-phenoxy]propionic acid and derivatives thereof as possessing herbicidal activity.